The aim of this game is for the player to survive as long as possible in this virus-spreading world. Starting the round by clicking the "Next Round" button or using space key. Within a short time, you need to decide where to go.
 is a virus that can infect others at the same place and similar to it, i.e. the same color or same number. Then infected ones will take 2 rounds to upgrade from infected to a virus.
 is the virus just in a different display mode, it will infect its similar ones who starts with 3 or ends with 2.
 is super virus upgraded from virus after game level 3. It can infect all kinds at the same place.
 are 3 types of medicines with different strength that can cure infected ones in full. Everyone will be immunised from infection for the next round after being cured. The player can pick them up when passing by and will always be cured in priority.
 can cure everyone when it passes by. But it will only be available once in one game level when reaching high infection percentage.
